• Download source - 46 Kb
• Download demo project - 79 Kb

Introduction

This is an 3d opengl graph ActiveX control based on the OpenGL library, which allows you to plot three-dimensional data. The control is entirely written on ATL/STL, and does not link to MFC libraries.

The control can perform the following functions:

• Axis customization, including customizable font, colors, and titles.
• Plot a large number of points and updating one or more plots on the graph with new data, replacing the old plot with the new plot.
• Plot the multiple elements with individual properties such as line and point color, line width, and point size.
• Lighting
• Plot styles: {0 (Lines); 1 (Points); 2 (LinePoint); 3 (Surface)}
• By setting the Projection property you should be able to change the viewing to: (0) Perspective (in which objects that are closer appear larger), and (1) Orthographic (in which the sizes and angles between objects are maintained no matter what their distance from the viewer).
• By setting the TrackMode property you should be able to do: (1) Zooming, (2) Rotation, and (3) Panning at runtime.

About the Code

To use this control, embed it in an application that supports the use of ActiveX controls. Microsoft Visual Basic applications, all MS Office applications, VBScript and JavaScript in the HTA or Internet Explorer applications, and applications created with the Microsoft Developer Studio’s AppWizard can support the use of ActiveX controls.

Before you start, the control must be register as a COM component using Regsvr32.exe. Regsvr32 takes one argument the DLL or control to register and any of several command-line switches, the most notable of which is /u to uninstall a control. By default that is, when run with only a dll or ocx Regsvr32.exe registers the control.

Note: you must do this on every computer that you are going to use the control!

For more information on how to register and how to include the control in a VC Project, refer to my article 3D Graph ActiveX Control.
 

Bellow are two listings that demonstrates how to use the control to draw a Torus:

C++

//
//
// Plot Torus
//
void CDemoDlg::OnButton1() 
{
   m_Graph3D.SetCaption ("Torus");
   m_Graph3D.ClearGraph(); // Clear all data
   m_Graph3D.AddElement(); // Add an element to element list

   m_Graph3D.SetElementLineColor(0, RGB(255,0,0));
   m_Graph3D.SetElementType(0, 3); // draw surface
   
   double x,y,z,ti,tj;
   
   for (int i = 0; i < 41; i++)
   {
      ti = (i - 20.0)/20.0 * 3.15;
      
      for (int j = 0; j < 41 ; j++) 
      {
	   tj = (j - 20.0)/20.0 * 3.15;
           
	   x = (cos(tj) + 3.0) * cos(ti);
	   y = sin(tj);
	   z = (cos(tj) + 3.0) * sin(ti);

           m_Graph3D.PlotXYZ(x,y,z,0); 
     }
   }

   //m_Graph3D.SetRange (-4, 4, -1, 1, -4, 4);
   m_Graph3D.AutoRange();
}

Visual Basic

'''''''''''''''''''''''''''''' 
' Look at the Demo3D.hta file 
' Double click on file to start the demo
'
' Plot Torus
'
Sub Torus

   With Graph3D
	.ClearGraph
  	.AddElement
        .Caption = "Torus"
	.ElementType(0) = 3 'Draw Surface

   For i = 0 To 41
    ti = (i - 20.0)/20.0 * 3.15

    For j = 0 To 41 
	
	tj = (j - 20.0)/20.0 * 3.15

	x = (cos(tj) + 3.0) * cos(ti)
	y = sin(tj)
	z = (cos(tj) + 3.0) * sin(ti)
	.PlotXYZ x,y,z,0
        
     Next
    Next
    	.Autorange
  End With
End Sub

List of Control Properties:

Graph

•  short Appearance
•  long BorderStyle
•  VARIANT_BOOL BorderVisible
•  BSTR Caption
•  IFontDisp* Font
•  OLE_COLOR BackColor
•  OLE_COLOR CaptionColor 
•  short TrackMode
•  short Projection
•  BSTR XLabel
•  BSTR YLabel
•  BSTR ZLabel
•  short XGridNumber
•  short YGridNumber
•  short ZGridNumber
•  OLE_COLOR XGridColor
•  OLE_COLOR YGridColor
•  OLE_COLOR ZGridColor

  Elements

•  OLE_COLOR ElementLineColor(long ElementID, OLE_COLOR newVal)
•  OLE_COLOR ElementPointColor(long ElementID, OLE_COLOR newVal)
•  float ElementLineWidth(long ElementID, float newVal)
•  float ElementPointSize(long ElementID, float newVal)
•  short ElementType(long ElementID)
•  BOOL ElementShow(long ElementID)
•  BOOL ElementSurfaceFill(long ElementID)
•  BOOL ElementSurfaceFlat(long ElementID)
•  BOOL ElementLight(long ElementID
•  short ElementLightingAmbient(long ElementID)
•  short ElementLightingDiffuse(long ElementID)
•  short ElementLightingSpecular(long ElementID)
•  short ElementMaterialAmbient(long ElementID)
•  short ElementMaterialDiffuse(long ElementID)
•  short ElementMaterialSpecular(long ElementID)
•  short ElementMaterialShinines(long ElementID)
•  short ElementMaterialShinines(long ElementID)
•  short ElementMaterialEmission(long ElementID)

List of Control Methods:

Graph

•  void SetRange(double xmin, double xmax, double ymin, double ymax, double zmin, double zmax)
•  void AutoRange()
•  void ShowPropertyPages()

  Elements

•  void AddElement()
•  void DeleteElement(long ElementID)
•  void ClearGraph()
•  void PlotXYZ(double x, double y, double z, long ElementID)
•  void SetLightCoordinates(long ElementID, float x, float y, float z)

Cost: One bottle wine. :-)

Enjoy!

Note: I am not expert on OpenGL, therefore all good suggestions, code and help for imporving the control are welcome!